Compressowieter



No. 753,015. PATENTED FEB. 23,1904.

w. J. TRETGH.

GOMPRBSSOMETER. APPLICATION FILED NOV. 19, 1903.

K0 Morn.

Patented February 23, 1904.

UNITED STATES PATENT OFFICE.

WILLIAM J. TRETCH, OF PLULADELPHIA, PENNSYLVANIA, ASSIGNOR TO FREDERICKA. RIEHLE, OF PHILADELPHIA, PENNSYLVANIA.

COMPRESSOIVIETER.

SPECIFICATION forming part of Letters Patent No. 753,015, dated February23, 1904.

T0 at whom it may concern:

Be it known that I, WILLIAM J. Tnnron, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented .a new and useful Improvement inCompressometers, of which the following is a specification.

My invention relates to compressometers.

It consists of means for determining with great accuracy the reductionin the length or other dimensions of a specimen subjected to compressionin a testing-machine.

It also consists of electric means for calling the attention of anobserver to the necessity distance above the block 3 is a beam 5, whichsupports a head-block 6. Between the blocks 3 and 6 is placed thespecimen 7 the resistance to compressionor the elastic limit of which isto be tested. As shown, the test piece or specimen is a cylindric'bar,which may of course be of metal, stone, wood, or other material.

In the lower face of the head-block 6 are drilled holes 8, in whichsockets 9 are secured by set-screws 10. Directly beneath these in theblock 3 are holes 11, threaded to receive adjusting-screws 12. It isunderstood that the socket 9 and the screws 12 are on diametricallyopposite sides of the test-piece 7. E tending between the sockets 9 andthe screws 12 and supported by the former are two gages 13. As these arealike, except in being right and left, I will describe them in thesingular. The gage consists of two parallel bars 14 15, provided withguides 16 17 by which they are maintained in sliding contact. SecuredApplication filed November 19, 1903. Serial No. 181,791. (No model-) tothe bar 15 is a laterally-extending bracket 18, divided into two partsby a strip 19, of insulating material. The outer portion of the bracket18 supports a micrometer-gage 20, the pin 21 of which projectsvertically through its case, as shown. Pivoted to the bar 15 is amultiplying-lever 22, the shorter end of which bears against a lug 23 onthe bar-J4. The faces of the bars 14 15 may be marked with aVernier-scale 24. To the outer part of said bracket 18 is attached awire 25, a second wire 26 being attached to any part of the device inmetallic communication with the corresponding lever 22. Within thecircuit of the wires 26 and 27 are a battery 28, a magneto-bell29, and aswitch 30.

The operation is as follows: The. parts being assembled as shown, theadjusting-screws 12 are set to give an initial zero-reading on thescales 2A of both gages 13. The desired compressive force having beenapplied through the beam 5, the longitudinal reduc tion of thetest-piece 7 will be indicated by the scale 24. Deflection in anydirection from a true rectilinear movement of the beam 5 and box 1toward each other will ordinarily be compensated for by an equivalentmovement of the block 3 in the concave base 1; but to secure stillgreater accuracy I have provided the two oppositely-disposed gages themean reading of whose'scales will give the true compression.

When it is desired to measure the reduction in length of a specimenunder a given stress, the test-piece is placed in the machine, as shownin the drawings. The micrometer-gages are then set at zero, and theadjusting-screws are raised until both gage-pins 21 contact withthelevers 22, which contact is shown by the ringing of the bell 29. Theeffect of compression is of course to raise the outer end of the readingof both gages, contact with the first gage is released after reading andcontact made in like manner between the pin of the and that by means ofthe screws 12 of the lower block any desired adjustment, either of theVernier-scales or of the micrometergages, may be made. It will also beseen that the micrometer-gages are so supported as to be removed fromdanger of injury, either in the placing or the breaking of the testspecimen,

and yet so that the scales on their heads 31 may be conveniently read.

By the term compression-blocks wherever used I wish to be understood asincludingany form of blocks adapted to be forced together by means of atesting-machine and to receive between them atest-piece the compre'ssionof which is to be measured.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. A compressometer including compression-blocks adapted to receivebetween them a test-piece, a gage operatively connected to saidcompression-blocks to measure the reduction of distance between them anda portion on which one of said blocks bears, said portion and said blockhaving the one a convex and the other a concave surface.

2. A compressometer including compression-blocks adapted to retainbetween them a test-piece, a gage and means in the faces of said blocksfor supporting said gage between them.

3. A compressometer comprising compression-blocks adapted to retainbetween them a test-piece, a plurality of gages and means in the facesof said blocks for supporting said gages at opposite sides of andsubstantially equal distances from said test-piece.

4:. A compressometer including compression-blocks adapted to retainbetween them a vertically-disposed test-piece, a gage suspended from theupper of said blocks and adjustable means in the lower of said blocksbearing against said gage.

5. A compressometer comprising compression-blocks adapted to containbetween them a test -piece, a gage supported between said blocks and anadjusting-screw in one of said blocks bearing against said gage wherebysaid gage may be brought to an initial zero.

6. In a compressometer, a gage comprising portions adapted to relativemovement, a multiplyinglever operatively connected to said portions,contact-points connected to each of said portions and electricallyinsulated from each other, one of said contact-points being adjacent theend of said multiplying-lever, a

micrometer-screw for adjusting the position of the other of saidcontact-points and an electric circuit, the flow of current throughwhich is alterable by the contact of said points.

WILLIAM J. TRETCH. Witnesses:

W. O. DU CoM'r, Jr., H. R. FIELIs.

